PKCS11机制差异+ JAVA

Question

I'm implementing functions with PKCS11 mechanisms - CKM_RSA_PKCS and CKM_RSA_X_509. I know that both are implemented in Botan C++ library, but I have to find equivalents in Java. Second problem is what's the difference between both of them?

Answer 1

CKM_RSA_PKCS refers to the PKCS#1 v1.5 standard (see RFC3447 ) for RSA encryption and digital signatures. In Java JCE, it is typically the default choice for RSA.

• For digital signatures, pass "MD5WithRSA" , "SHA1WithRSA" , etc to Signature.getInstance()
• For encryption, pass "RSA/None/PKCS1Padding" to Cipher.getInstance() .

CKM_RSA_X_509 refers to the textbook (or raw) RSA algorithm, that is, the one where no padding is defined. In this case, you can simply pass "RSA/None/NoPadding" to Cipher.getInstance() . Signature can be done with decryption, wheres verification can be done with encryption (followed by comparison).

I would avoid implementing and using raw RSA though, unless you have specific use cases in mind. PKCS#1v 1.5 signatures are more secure. For enciphering though, I wouldn't actually recommend to use either of them, because they are both unsecure. It's better to rely only on PKCS#1 OAEP ( CKM_RSA_PKCS_OAEP ); for that, you pass "RSA/None/OAEPWithSHA1AndMGF1Padding" to Cipher.getInstance() .